Analysis of a biological sample to discern its characteristics, and to get information about various biological targets is in demand both in biology and medicine. A variety of methods may be employed for analyzing the biological sample to detect, inter alia, the presence, absence, concentration, and/or spatial distribution of the biological targets. For example, detection of proteins in histological sections or cytological preparations may be performed using histochemistry, immunohistochemistry (IHC), or immunofluorescence.
However, many of the existing techniques for detecting targets in a biological sample have limitations in terms of sensitivity, accuracy and/or multiplexing abilities. Particularly, detection of multiple targets in a single biological sample is often limited to the detection of only a few targets (about 4 to 5 targets) at a time. For example, the number of targets that are accurately detectable in a single tissue sample during an immunofluorescence assay is limited by the sensitivity of florescence-based detection system to resolve overlapping signals. Hence, additional biological samples from the source may often be required to get information about all the relevant targets.
Analysis of multiple biological samples limits the ability to accurately determine relative characteristics (e.g., the presence, absence, concentration, and/or spatial distribution) of a plurality of different targets in the biological sample. Moreover, in certain instances, a limited amount of sample may only be available for analysis. Thus, methods, agents, and devices capable of analyzing an individual biological sample to detect a plurality of different targets in the biological sample are needed.